Tracking system and method for use in surveying amusement park equipment

ABSTRACT

A dynamic signal to noise ratio tracking system enables detection and tracking of amusement park equipment within the field of view of the tracking system. The tracking system may include an emitter configured to emit electromagnetic radiation within an area, a detector configured to detect electromagnetic radiation reflected back from vehicles within the area, and a control unit configured to evaluate signals from the detector to survey the amusement park equipment to determine whether the equipment has degraded or shifted.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/717,921, entitled “TRACKING SYSTEM AND METHOD FOR USE IN SURVEYINGAMUSEMENT PARK EQUIPMENT” filed on May 20, 2015, which claims thebenefit of U.S. Provisional Application No. 62/001,551, filed May 21,2014, which are incorporated herein by reference in their entireties forall purposes.

BACKGROUND

The present disclosure relates generally to the field of trackingsystems and, more particularly, to methods and equipment used to enabletracking of elements in a variety of contexts through a dynamic signalto noise ratio tracking system.

Tracking systems have been widely used to track motion, position,orientation, and distance, among other aspects, of objects in a widevariety of contexts. Such existing tracking systems generally include anemitter that emits electromagnetic energy and a detector configured todetect the electromagnetic energy, sometimes after it has been reflectedoff an object. It is now recognized that traditional tracking systemshave certain disadvantages and that improved tracking systems aredesired for use in a variety of contexts, including amusement parkattractions, workplace monitoring, sports, fireworks displays, factoryfloor management, robotics, security systems, parking, andtransportation, among others.

BRIEF DESCRIPTION

In accordance with an embodiment of the present disclosure, an amusementpark surveying system includes an amusement park feature having aretro-reflective marker; an emitter configured to emit electromagneticradiation toward the retro-reflective marker; a detector configured todetect retro-reflection of the electromagnetic radiation from theretro-reflective marker while filtering electromagnetic radiation thatis not retro-reflected; and a control system communicatively coupled tothe detector and comprising processing circuitry configured to: monitorthe retro-reflected electromagnetic radiation from the retro-reflectivemarker against a reference signature of retro-reflected electromagneticradiation from the retro-reflective marker stored in memory; andidentify differences between the electromagnetic radiationretro-reflected by the retro-reflective marker and the referencesignature of retro-reflected electromagnetic radiation to evaluate acondition of the amusement park feature.

In accordance with another embodiment of the present disclosure, amethod of surveying amusement park features includes directingelectromagnetic radiation toward an amusement park feature positionedwithin an amusement park attraction area using an emitter, the amusementpark feature having a retro-reflective marker; detecting electromagneticradiation retro-reflected from the retro-reflective marker disposed onthe amusement park feature while filtering out electromagnetic radiationthat is not retro-reflected using a detector; monitoring theretro-reflected electromagnetic radiation from the retro-reflectivemarker against a reference signature of retro-reflected electromagneticradiation from the retro-reflective marker stored in memory usingprocessing circuitry of a control system in communication with thedetector; and identifying differences between the electromagneticradiation retro-reflected by the retro-reflective marker and thereference signature of retro-reflected electromagnetic radiation toevaluate a condition of the amusement park feature.

In accordance with a further embodiment of the present disclosure, asurvey system configured to survey amusement park features includes aretro-reflective marker; an emitter configured to emit electromagneticradiation toward the retro-reflective marker; a detector correlated toelectromagnetic radiation retro-reflected by the retro-reflective markerand configured to detect retro-reflection of the electromagneticradiation from the retro-reflective marker while filteringelectromagnetic radiation that is not retro-reflected; and a controlsystem communicatively coupled to the emitter and the detector andhaving processing circuitry configured to: monitor the retro-reflectedelectromagnetic radiation from the retro-reflective marker against areference signature of retro-reflected electromagnetic radiation fromthe retro-reflective marker stored in memory; and identify differencesbetween the electromagnetic radiation retro-reflected by theretro-reflective marker and the reference signature of retro-reflectedelectromagnetic radiation, including differences in position ororientation, to evaluate a condition of an amusement park feature; andwherein the emitter, the detector, and at least a portion of theprocessing circuitry of the control system are integrated with or form apart of surveying equipment, the surveying equipment comprising a totalstation, a robotic total station, an electronic distance meter, atheodolite, or any combination thereof.

DRAWINGS

These and other features, aspects, and advantages of the presentdisclosure will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a schematic diagram of a tracking system utilizing a dynamicsignal to noise ratio device to track objects, in accordance with anembodiment of the present disclosure;

FIG. 2 is a schematic diagram of another tracking system utilizing adynamic signal to noise ratio device to track objects, in accordancewith an embodiment of the present disclosure;

FIG. 3 is a schematic view of the tracking system of FIG. 1 tracking aretro-reflective marker on a person, in accordance with an embodiment ofthe present disclosure;

FIG. 4 is a schematic representation of an analysis performed by thetracking system of FIG. 1 in which position and movement of a person orobject is tracked in space and time, in accordance with an embodiment ofthe present disclosure;

FIG. 5 is an overhead view of a room with a grid pattern ofretro-reflective markers for tracking a position of people in the roomvia the tracking system of FIG. 1, in accordance with an embodiment ofthe present disclosure;

FIG. 6 is an elevational view of the tracking system of FIG. 1 trackinga person without tracking retro-reflective marker movement and withouttracking retro-reflective marker occlusion, in accordance with anembodiment of the present disclosure;

FIG. 7 is an elevational view of a room with a grid pattern ofretro-reflective markers disposed on a wall and a floor of the room fortracking a position of people and objects in the room via the trackingsystem of FIG. 1, in accordance with an embodiment of the presentdisclosure;

FIG. 8 illustrates cross-sections of retro-reflective markers havingdifferent coatings to enable different wavelengths of electromagneticradiation to be reflected back toward the detector of the trackingsystem of FIG. 1, in accordance with an embodiment of the presentdisclosure;

FIGS. 9A-9C depict the manner in which an object may be tracked in threespatial dimensions by the tracking system of FIG. 1, in accordance withan embodiment of the present disclosure;

FIG. 10 is a flow diagram illustrating an embodiment of a method oftracking reflection and controlling amusement park elements based on thetracked reflection using the tracking system of FIG. 1, in accordancewith an embodiment of the present disclosure;

FIG. 11 is a perspective view of the tracking system of FIG. 1 beingused in surveying equipment to determine changes in elevation orcoloration of structures, in accordance with an embodiment of thepresent disclosure;

FIG. 12 is a schematic representation of the manner in which thetracking system of FIG. 1 monitors the change in a surface condition ofa structure having a retro-reflective marker positioned under thesurface, in accordance with an embodiment of the present disclosure;

FIG. 13 is a perspective view of the tracking system of FIG. 1 beingused to survey an amusement park ride, including support structures anda track, to determine changes in structural elevation of the ride, inaccordance with an embodiment of the present disclosure;

FIG. 14 is a perspective view of the tracking system of FIG. 1 used tomonitor an amusement park ride vehicle and a flame effect, in accordancewith an embodiment of the present disclosure;

FIG. 15 is a cross-sectional side view of a flame-producing devicemonitored and controlled by the tracking system of FIG. 1, in accordancewith an embodiment of the present disclosure;

FIG. 16 is a perspective view of the tracking system of FIG. 1 beingused to monitor a height of ordinances in a firework show, in accordancewith an embodiment of the present disclosure;

FIG. 17 is a cross-sectional side view of an ordinance having anelectronic detonator and a retro-reflective marker attached to its outercasing to enable the ordinance to be tracked by the tracking system ofFIG. 1, in accordance with an embodiment of the present disclosure; and

FIG. 18 is a perspective view of a firework show usingrobotically-actuated cannons that are controlled by the tracking systemof FIG. 1, in accordance with an embodiment of the present disclosure.

DETAILED DESCRIPTION

Generally, tracking systems may use a wide variety of inputs obtainedfrom a surrounding environment to track certain objects. The source ofthe inputs may depend, for instance, on the type of tracking beingperformed and the capabilities of the tracking system. For example,tracking systems may use sensors disposed in an environment to activelygenerate outputs received by a main controller. The controller may thenprocess the generated outputs to determine certain information used fortracking. One example of such tracking may include tracking the motionof an object to which a sensor is fixed. Such a system might alsoutilize one or more devices used to bathe an area in electromagneticradiation, a magnetic field, or the like, where the electromagneticradiation or magnetic field is used as a reference against which thesensor's output is compared by the controller. As may be appreciated,such active systems, if implemented to track a large number of objectsor even people, could be quite expensive to employ andprocessor-intensive for the main controller of the tracking system.

Other tracking systems, such as certain passive tracking systems, mayperform tracking without providing an illumination source or the like.For instance, certain tracking systems may use one or more cameras toobtain outlines or rough skeletal estimates of objects, people, and soforth. However, in situations where background illumination may beintense, such as outside on a hot and sunny day, the accuracy of such asystem may be reduced due to varying degrees of noise received bydetectors of the passive tracking system.

With the foregoing in mind, it is now recognized that traditionaltracking systems have certain disadvantages and that improved trackingsystems are desired for use in a variety of contexts, includingamusement park attractions, workplace monitoring, sports, and securitysystems, among others. For instance, it is presently recognized thatimproved tracking systems may be utilized to enhance operations in avariety of amusement park settings and other entertainment attractions.

In accordance with one aspect of the present disclosure, a dynamicsignal to noise ratio tracking system uses emitted electromagneticradiation and, in some embodiments, retro-reflection, to enabledetection of markers and/or objects within the field of view of thetracking system. The disclosed tracking system may include an emitterconfigured to emit electromagnetic radiation in a field of view, asensing device configured to detect the electromagnetic radiationretro-reflected back from objects within the field of view, and acontroller configured to perform various processing and analysisroutines including interpreting signals from the sensing device andcontrolling automated equipment based on the detected locations of theobjects or markers. The disclosed tracking system may also be configuredto track several different objects at the same time (using the sameemission and detection features). In some embodiments, the trackingsystem tracks a location of retro-reflective markers placed on theobjects to estimate a location of the objects. As used herein,retro-reflective markers are reflective markers designed toretro-reflect electromagnetic radiation approximately back in thedirection from which the electromagnetic radiation was emitted. Morespecifically, retro-reflective markers used in accordance with thepresent disclosure, when illuminated, reflect electromagnetic radiationback toward the source of emission in a narrow cone. In contrast,certain other reflective materials, such as shiny materials, may undergodiffuse reflection where electromagnetic radiation is reflected in manydirections. Further still, mirrors, which also reflect electromagneticradiation, do not typically undergo retro-reflection. Rather, mirrorsundergo specular reflection, where an angle of electromagnetic radiation(e.g., light such as infrared, ultraviolet, visible, or radio waves andso forth) incident onto the mirror is reflected at an equal but oppositeangle (away from the emission source).

Retro-reflective materials used in accordance with the embodiments setforth below can be readily obtained from a number of commercial sources.One example includes retro-reflective tape, which may be fitted to anumber of different objects (e.g., environmental features, clothingitems, toys). Due to the manner in which retro-reflection occurs usingsuch markers in combination with the detectors 16 used in accordancewith the present disclosure, the retro-reflective markers cannot bewashed out by the sun or even in the presence of other emitters thatemit electromagnetic radiation in wavelengths that overlap with thewavelengths of interest. Accordingly, the disclosed tracking system maybe more reliable, especially in an outdoor setting and in the presenceof other electromagnetic emission sources, compared to existing opticaltracking systems.

While the present disclosure is applicable to a number of differentcontexts, presently disclosed embodiments are directed to, among otherthings, various aspects relating to tracking changes to certainstructures (e.g., building, support columns) within an amusement park,and, in some situations, controlling amusement park equipment (e.g.,automated equipment) based on information obtained from such a dynamicsignal to noise ratio tracking system. Indeed, it is presentlyrecognized that by using the disclosed tracking systems, reliable andefficient amusement park operations may be carried out, even thoughthere are a number of moving objects, guests, employees, sounds, lights,and so forth, in an amusement park, which could otherwise create highlevels of noise for other tracking systems, especially other opticaltracking systems that do not use retro-reflective markers in the mannerdisclosed herein.

In certain aspects of the present disclosure, a control system of theamusement park (e.g., a control system associated with a particular areaof the amusement park, such as a ride) may use information obtained bythe dynamic signal to noise ratio tracking system to monitor andevaluate information relating to people, machines, vehicles (e.g., guestvehicles, service vehicles), and similar features in the area to provideinformation that may be useful in the more efficient operation ofamusement park operations. For example, the information may be used todetermine whether certain automated processes may be triggered orotherwise allowed to proceed. The evaluated information pertaining tovehicles in the amusement park may include, for instance, a location, amovement, a size, or other information relating to automated machines,ride vehicles, and so forth, within certain areas of the amusement park.By way of non-limiting example, the information may be evaluated totrack people and machines to provide enhanced interactivity between thepeople and the machines, to track and control unmanned aerial vehicles,to track and control ride vehicles and any show effects associated withthe ride vehicle, and so forth.

Certain aspects of the present disclosure may be better understood withreference to FIG. 1, which generally illustrates the manner in which adynamic signal to noise ratio tracking system 10 (hereinafter referredto as “tracking system 10”) may be integrated with amusement parkequipment 12 in accordance with present embodiments. As illustrated, thetracking system 10 includes an emitter 14 (which may be all or a part ofan emission subsystem having one or more emission devices and associatedcontrol circuitry) configured to emit one or more wavelengths ofelectromagnetic radiation (e.g., light such as infrared, ultraviolet,visible, or radio waves and so forth) in a general direction. Thetracking system 10 also includes a detector 16 (which may be all or apart of a detection subsystem having one or more sensors, cameras, orthe like, and associated control circuitry) configured to detectelectromagnetic radiation reflected as a result of the emission, asdescribed in further detail below.

To control operations of the emitter 14 and detector 16 (emissionsubsystem and detection subsystem) and perform various signal processingroutines resulting from the emission, reflection, and detection process,the tracking system 10 also includes a control unit 18 communicativelycoupled to the emitter 14 and detector 16. Accordingly, the control unit18 may include one or more processors 20 and one or more memory 22,which may generally referred to herein as “processing circuitry.” By wayof specific but non-limiting example, the one or more processors 20 mayinclude one or more application specific integrated circuits (ASICs),one or more field programmable gate arrays (FPGAs), one or more generalpurpose processors, or any combination thereof. Additionally, the one ormore memory 22 may include volatile memory, such as random access memory(RAM), and/or non-volatile memory, such as read-only memory (ROM),optical drives, hard disc drives, or solid-state drives. In someembodiments, the control unit 18 may form at least a portion of acontrol system configured to coordinate operations of various amusementpark features, including the equipment 12. As described below, such anintegrated system may be referred to as an amusement park attraction andcontrol system.

The tracking system 10 is specifically configured to detect a positionof an illuminated component, such as a retro-reflective marker 24 havinga properly correlated retro-reflective material relative to a grid,pattern, the emission source, stationary or moving environmentalelements, or the like. In some embodiments, the tracking system 10 isdesigned to utilize the relative positioning to identify whether acorrelation exists between one or more such illuminated components and aparticular action to be performed by the amusement park equipment 12,such as triggering of a show effect, dispatch of a ride vehicle, closureof a gate, synchronization of security cameras with movement, and so on.More generally, the action may include the control of machine movement,image formation or adaptation, and similar processes.

As illustrated, the retro-reflective marker 24 is positioned on anobject 26, which may correspond to any number of static or dynamicfeatures. For instance, the object 26 may represent boundary features ofan amusement park attraction, such as a floor, a wall, a gate, or thelike, or may represent an item wearable by a guest, park employee, orsimilar object. Indeed, as set forth below, within an amusement parkattraction area, many such retro-reflective markers 24 may be present,and the tracking system 10 may detect reflection from some or all of themarkers 24, and may perform various analyses based on this detection.

Referring now to the operation of the tracking system 10, the emitter 14operates to emit electromagnetic radiation, which is represented by anexpanding electromagnetic radiation beam 28 electromagnetic radiationbeam 28 electromagnetic radiation beam 28 for illustrative purposes, toselectively illuminate, bathe, or flood a detection area 30 in theelectromagnetic radiation. Electromagnetic radiation beam 28 is intendedto generally represent any form of electromagnetic radiation that may beused in accordance with present embodiments, such as forms of light(e.g., infrared, visible, UV) and/or other bands of the electromagneticspectrum (e.g., radio waves and so forth). However, it is also presentlyrecognized that, in certain embodiments, it may be desirable to usecertain bands of the electromagnetic spectrum depending on variousfactors. For example, in one embodiment, it may be desirable to useforms of electromagnetic radiation that are not visible to the human eyeor within an audible range of human hearing, so that the electromagneticradiation used for tracking does not distract guests from theirexperience. Further, it is also presently recognized that certain formsof electromagnetic radiation, such as certain wavelengths of light(e.g., infrared) may be more desirable than others, depending on theparticular setting (e.g., whether the setting is “dark,” or whetherpeople are expected to cross the path of the beam). Again, the detectionarea 30 may correspond to all or a part of an amusement park attractionarea, such as a stage show, a ride vehicle loading area, a waiting areaoutside of an entrance to a ride or show, and so forth.

The electromagnetic radiation beam 28, in certain embodiments, may berepresentative of multiple light beams (beams of electromagneticradiation) being emitted from different sources (all part of an emissionsubsystem). Further, in some embodiments the emitter 14 is configured toemit the electromagnetic radiation beam 28 at a frequency that has acorrespondence to a material of the retro-reflective marker 24 (e.g., isable to be reflected by the retro-reflective elements of the marker 24).For instance, the retro-reflective marker 24 may include a coating ofretro-reflective material disposed on a body of the object 26 or a solidpiece of material coupled with the body of the object 26. By way of morespecific but non-limiting example, the retro-reflective material mayinclude spherical and/or prismatic reflective elements that areincorporated into a reflective material to enable retro-reflection tooccur. Again, in certain embodiments many such retro-reflective markers24 may be present, and may be arranged in a particular pattern stored inthe memory 22 to enable further processing, analysis, and controlroutines to be performed by the control unit 18 (e.g., control system).

The retro-reflective marker 24 may reflect a majority of theelectromagnetic radiation (e.g., infrared, ultraviolet, visiblewavelengths, or radio waves and so forth) incident from theelectromagnetic radiation beam 28 back toward the detector 16 within arelatively well-defined cone having a central axis with substantiallythe same angle as the angle of incidence. This reflection facilitatesidentification of a location of the retro-reflective marker 24 by thesystem 10 and correlation thereof to various information stored in thememory 22 (e.g., patterns, possible locations). This locationinformation (obtained based on the reflected electromagnetic radiation)may then be utilized by the control unit 18 to perform various analysisroutines and/or control routines, for example to determine whether tocause triggering or other control of the amusement park equipment 12.

Specifically, in operation, the detector 16 of the system 10 mayfunction to detect the electromagnetic radiation beam 28 retro-reflectedfrom the retro-reflective marker 24 and provide data associated with thedetection to the control unit 18 via communication lines 31 forprocessing. The detector 16 may operate to specifically identify themarker 24 based on certain specified wavelengths of electromagneticradiation emitted and reflected and, thus, avoid issues with falsedetections. For example, the detector 16 may be specifically configuredto detect certain wavelengths of electromagnetic radiation (e.g.,corresponding to those emitted by the emitter 14) through the use ofphysical electromagnetic radiation filters, signal filters, and thelike. Further, the detector 16 may utilize a specific arrangement ofoptical detection features and electromagnetic radiation filters tocapture substantially only retro-reflected electromagnetic radiation.

For example, the detector 16 may be configured to detect wavelengths ofelectromagnetic radiation retro-reflected by the retro-reflectivemarkers 24 while filtering wavelengths of electromagnetic radiation notretro-reflected by the markers 24, including those wavelengths ofinterest. Thus, the detector 16 may be configured to specifically detect(e.g., capture) retro-reflected electromagnetic radiation while notdetecting (e.g., capturing) electromagnetic radiation that is notretro-reflected. In one embodiment, the detector 16 may utilize thedirectionality associated with retro-reflection to perform thisselective filtering. Accordingly, while the detector 16 receiveselectromagnetic radiation from a variety of sources (includingspuriously reflected electromagnetic radiation, as well as environmentalelectromagnetic radiation), the detector 16 is specifically configuredto filter out all or substantially all spuriously reflected signalswhile retaining all or substantially all intended signals. Thus, thesignal-to-noise ratio of signals actually processed by the detector 16and control unit 18 is very high, regardless of the signal-to-noiseratio that exists for the electromagnetic bands of interest outside ofthe detector 16.

For example, the detector 16 may receive retro-reflected electromagneticradiation (e.g., from the retro-reflective markers 24) and ambientelectromagnetic radiation from within an area (e.g., guest attractionarea). The ambient electromagnetic radiation may be filtered, while theretro-reflected electromagnetic radiation, which is directional, may notbe filtered (e.g., may bypass the filter). Thus, in certain embodiments,the “image” generated by the detector 16 may include a substantiallydark (e.g., black or blank) background signal, with substantially onlyretro-reflected electromagnetic radiation producing contrast.

In accordance with certain embodiments, the retro-reflectedelectromagnetic radiation may include different wavelengths that aredistinguishable from one another. In one embodiment, the filters of thedetector 16 may have optical qualities and may be positioned within thedetector such that the optical detection devices of the detector 16substantially only receive electromagnetic wavelengths retro-reflectedby the retro-reflective markers 24 (or other retro-reflective elements),as well as any desired background wavelengths (which may providebackground or other landscape information). To produce signals from thereceived electromagnetic radiation, as an example, the detector 16 maybe a camera having a plurality of electromagnetic radiation capturingfeatures (e.g., charge-coupled devices (CCDs) and/or complementary metaloxide semiconductor (CMOS) sensors corresponding to pixels). In oneexample embodiment, the detector 16 may be an Amp® high dynamic range(HDR) camera system available from Contrast Optical Design andEngineering, Inc. of Albuquerque, N. Mex.

Because retro-reflection by the retro-reflective markers 24 is such thata cone of reflected electromagnetic radiation is incident on thedetector 16, the control unit 18 may in turn correlate a center of thecone, where the reflected electromagnetic radiation is most intense, toa point source of the reflection. Based on this correlation, the controlunit 18 may identify and track a location of this point source, or mayidentify and monitor a pattern of reflection by many suchretro-reflective markers 24.

For instance, once the control unit 18 receives the data from thedetector 16, the control unit 18 may employ known visual boundaries oran established orientation of the detector 16 to identify a location(e.g., coordinates) corresponding to the detected retro-reflectivemarker 24. When multiple stationary retro-reflective markers 24 arepresent, the control unit 18 may store known positions (e.g., locations)of the retro-reflective markers 24 to enable reflection patternmonitoring. By monitoring a reflection pattern, the control unit 18 mayidentify blockage (occlusion) of certain retro-reflective markers 24 byvarious moving objects, guests, employees, and so forth. It should alsobe noted that the bases for these comparisons may be updated based on,for example, how long a particular retro-reflective marker 24 has beenpositioned and used in its location. For instance, the stored pattern ofreflection associated with one of the markers 24 may be updatedperiodically during a calibration stage, which includes a time periodduring which no objects or people are expected to pass over the marker24. Such re-calibrations may be performed periodically so that a markerthat has been employed for an extended period of time and has lost itsretro-reflecting capability is not mistaken for a detected occlusionevent.

In other embodiments, in addition to or in lieu of tracking one or moreof the retro-reflective markers 24, the tracking system 10 may beconfigured to detect and track various other objects located within thedetection area 30. Such objects 32 may include, among other things, ridevehicles, people (e.g., guests, employees), and other moving parkequipment. For example, the detector 16 of the system 10 may function todetect the electromagnetic radiation beam 28 bouncing off of an object32 (without retro-reflective markers 24) and provide data associatedwith this detection to the control unit 18. That is, the detector 16 maydetect the object 32 based entirely on diffuse or specular reflection ofelectromagnetic energy off the object 32. In some embodiments, theobject 32 may be coated with a particular coating that reflects theelectromagnetic radiation beam 28 in a detectable and predeterminedmanner. Accordingly, once the control unit 18 receives the data from thedetector 16, the control unit 18 may determine that the coatingassociated with the object 32 reflected the electromagnetic radiation,and may also determine the source of the reflection to identify alocation of the object 32.

Whether the retro-reflective markers 24 are stationary or moving, theprocess of emitting the electromagnetic radiation beam 28, sensing ofthe reflected electromagnetic radiation from the retro-reflectivemarkers 24 (or objects 32 with no or essentially no retro-reflectivematerial), and determining a location of the retro-reflective marker 24or object 32 may be performed by the control unit 18 numerous times overa short period. This process may be performed at distinct intervals,where the process is initiated at predetermined time points, or may beperformed substantially continuously, such that substantiallyimmediately after the process is completed, it is re-initiated. Inembodiments where the retro-reflective markers 24 are stationary and thecontrol unit 18 performs retro-reflective pattern monitoring to identifymarker blockage, the process may be performed at intervals to obtain asingle retro-reflective pattern at each interval. This may be consideredto represent a single frame having a reflection pattern corresponding toa pattern of blocked and unblocked retro-reflective markers 24.

On the other hand, such procedures may essentially be performedcontinuously to facilitate identification of a path and/or trajectorythrough which the retro-reflective marker 24 has moved. The marker 24,moving within the detection area 30, would be detected over a particulartimeframe or simply in continuous series. Here, the pattern ofreflection would be generated and identified over a time period.

In accordance with the embodiments set forth above, the detector 16 andcontrol unit 18 may operate on a variety of different timeframesdepending on the tracking to be performed and the expected movement ofthe tracked object through space and time. As an example, the detector16 and the control unit 18 may operate in conjunction to complete alllogical processes (e.g., updating analysis and control signals,processing signals) in the time interval between the capture events ofthe detector 16. Such processing speeds may enable substantiallyreal-time tracking, monitoring, and control where applicable. By way ofnon-limiting example, the detector capture events may be betweenapproximately 1/60 of a second and approximately 1/30 of a second, thusgenerating between 30 and 60 frames per second. The detector 16 and thecontrol unit 18 may operate to receive, update, and process signalsbetween the capture of each frame. However, any interval between captureevents may be utilized in accordance with certain embodiments.

Once a particular pattern of retro-reflection has been detected, adetermination may be made by the control unit 18 as to whether thepattern correlates to a stored pattern identified by the control unit 18and corresponding to a particular action to be performed by theamusement park equipment 12. For example, the control unit 18 mayperform a comparison of a position, path, or trajectory of theretro-reflective marker 24 with stored positions, paths, or trajectoriesto determine an appropriate control action for the equipment 12.Additionally or alternatively, as described in further detail below, thecontrol unit 18 may determine whether a particular pattern obtained at aparticular time point correlates to a stored pattern associated with aparticular action to be performed by the amusement park equipment 12.Further still, the control unit 18 may determine whether a set ofparticular patterns obtained at particular time points correlate to astored pattern change associated with a particular action to beperformed by the amusement park equipment 12.

While the control unit 18 may cause certain actions to be automaticallyperformed within the amusement park in the manner set forth above, itshould be noted that similar analyses to those mentioned above may alsobe applied to the prevention of certain actions (e.g., where the parkequipment 12 blocks action or is blocked from performing an action). Forexample, in situations where a ride vehicle can be automaticallydispatched, the control unit 18, based upon tracking changes in theretro-reflective markers 24, may halt automatic dispatching, or may evenprevent dispatching by a ride operator until additional measures aretaken (e.g., additional confirmations that the ride vehicle is clearedfor departure). This type of control may be applied to other amusementpark equipment, as well. For example, flame effects, fireworks, orsimilar show effects may be blocked from being triggered, may bestopped, or may be reduced in intensity, due to intervention by thecontrol unit 18 as a result of certain pattern determinations asdescribed herein.

Having generally described the configuration of the system 10, it shouldbe noted that the arrangement of the emitter 14, detector 16, controlunit 18, and other features may vary based on application-specificconsiderations and the manner in which the control unit 18 performsevaluations based on electromagnetic radiation from the retro-reflectivemarkers 24. In the embodiment of the tracking system 10 illustrated inFIG. 1, the emitter 14 and the sensor or detector 16 are integralfeatures such that a plane of operation associated with the detector 16is essentially overlapping with a plane of operation associated with theemitter 14. That is, the detector 16 is located in substantially thesame position as the emitter 14, which may be desirable due to theretro-reflectivity of the markers 24. However, the present disclosure isnot necessarily limited to this configuration. For instance, as notedabove, retro-reflection may be associated with a cone of reflection,where the highest intensity is in the middle of the reflected cone.Accordingly, the detector 16 may be positioned within an area where thereflected cone of the retro-reflective markers is less intense than itscenter, but may still be detected by the detector 16.

By way of non-limiting example, in some embodiments, the emitter 14 andthe detector 16 may be concentric. However, the detector 16 (e.g., aninfrared camera) may be positioned in a different location with respectto the emitter 14, which may include an infrared light bulb, one or morediode emitters, or similar source. As illustrated in FIG. 2, the emitter14 and detector 16 are separate and are positioned at differentlocations on an environmental feature 40 of an amusement attraction area(e.g., a wall or ceiling). Specifically, the emitter 14 of FIG. 2 ispositioned outside of a window 42 of a storefront containing othercomponents of the system 10. The detector 16 of FIG. 2 is positionedaway from the emitter 14, but is still oriented to detectelectromagnetic radiation reflected from the retro-reflective marker 24and originating from the emitter 14.

For illustrative purposes, arrows 44, 46 represent a light beam (a beamof electromagnetic radiation) being emitted from the emitter 14 (arrow44) into the detection area 30, retro-reflected by the retro-reflectivemarker 24 on the object 26 (arrow 46), and detected by the detector 16.The light beam represented by the arrow 44 is merely one of numerouselectromagnetic radiation emissions (light beams) that flood orotherwise selectively illuminate the detection area 30 from the emitter14. It should be noted that still other embodiments may utilizedifferent arrangements of components of the system 10 andimplementations in different environments in accordance with the presentdisclosure.

Having now discussed the general operation of the tracking system 10 todetect a position of retro-reflective markers 24 and/or objects 32, asillustrated in FIG. 1, certain applications of the tracking system 10will be described in further detail below. For example, it may bedesirable to track the locations of people within a particular areathrough the use of the disclosed tracking systems. This may be useful,for example, for controlling lines in a ride vehicle loading area,controlling access to different areas, determining appropriate instanceswhen show effects can be triggered, determining appropriate instanceswhen certain automated machinery can be moved, and may also be usefulfor assisting a live show performance (e.g., blocking actors on astage). That is, during performances, actors are supposed to be standingat particular positions on the stage at certain times. To ensure thatthe actors are hitting their appropriate positions at the right time,the tracking system 10 may be installed above the stage and used totrack the positions and/or motion of all the actors on the stage.Feedback from the tracking system 10 may be utilized to evaluate howwell the actors are hitting the desired spots on the stage.

In addition to blocking on a stage, the tracking system 10 may be usedin contexts that involve tracking and/or evaluating shoppers in a storeor other commercial setting. That is, a store may be outfitted with thedisclosed tracking systems 10 in order to determine where guests arespending time within the store. Instead of triggering a show effect,such tracking systems 10 may be used to monitor the flow of peoplewithin the store and control the availability of certain items as aresult, control the flow of movement of people, etc. For instance,information collected via the disclosed tracking systems 10 may be usedto identify and evaluate which setups or displays within the store aremost attractive, to determine what items for sale are the most popular,or to determine which areas of the store, if any, are too crowded. Thisinformation may be analyzed and used to improve the store layout,product development, and crowd management, among other things.

It should be noted that other applications may exist for trackingpositions of people, objects, machines, etc. within an area other thanthose described above. Presently disclosed tracking systems 10 may beconfigured to identify and/or track the position and movement of peopleand/or objects within the detection area 30. The tracking system 10 mayaccomplish this tracking in several different ways, which wereintroduced above and are explained in further detail below. It should benoted that the tracking system 10 is configured to detect a position ofone or more people, one or more objects 32, or a combination ofdifferent features, at the same time in the same detection area 30 usingthe single emitter 14, detector 16, and control unit 18. However, theuse of multiple such emitters 14, detectors 16, and control units 18 isalso within the scope of the present disclosure. Accordingly, there maybe one or more of the emitters 14 and one or more of the detectors 16 inthe detection area 30. Considerations such as the type of tracking to beperformed, the desired range of tracking, for redundancy, and so forth,may at least partially determine whether multiple or a single emitterand/or detector are utilized.

For instance, as noted above, the tracking system 10 may generally beconfigured to track a target moving in space and in time (e.g., withinthe detection area 30 over time). When a single detection device (e.g.,detector 16) is utilized, the tracking system 10 may monitorretro-reflected electromagnetic radiation from a defined orientation totrack a person, object, etc. Because the detector 16 has only oneperspective, such detection and tracking may, in some embodiments, belimited to performing tracking in only one plane of movement (e.g., thetracking is in two spatial dimensions). Such tracking may be utilized,as an example, in situations where the tracked target has a relativelylow number of degrees of freedom, such as when movement is restricted toa constrained path (e.g., a track). In one such embodiment, the targethas a determined vector orientation.

On the other hand, when multiple detection devices are utilized (e.g.,two or more of the detectors 16) to track a target in both space andtime, the tracking system 10 may monitor retro-reflected electromagneticradiation from multiple orientations. Using these multiple vantagepoints, the tracking system 10 may be able to track targets havingmultiple degrees of freedom. In other words, the use of multipledetectors may provide both vector orientation and range for the trackedtarget. This type of tracking may be particularly useful in situationswhere it may be desirable to allow the tracked target to haveunrestricted movement in space and time.

Multiple detectors may also be desirable for redundancy in the tracking.For example, multiple detection devices applied to scenarios wheremovement of the target is restricted, or not, may enhance thereliability of the tracking performed by the tracking system 10. The useof redundant detectors 16 may also enhance tracking accuracy, and mayhelp prevent geometric occlusion of the target by complex geometricsurfaces, such as winding pathways, hills, folded clothing, openingdoors, and so on.

In accordance with one aspect of the present disclosure, the trackingsystem 10 may track relative positions of multiple targets (e.g.,people, objects, machines) positioned within the detection area 30through the use of the retro-reflective markers 24. As illustrated inFIG. 3, the retro-reflective markers 24 may be disposed on a person 70.Additionally or alternatively, the marker 24 may be positioned on amachine or other object (e.g., object 26). Accordingly, the techniquesdisclosed herein for tracking movement of the person 70 in space andtime may also be applied to movement of an object in the amusement park,either in addition to the person 70 or as an alternative to the person70. In such embodiments, the marker 24 may be positioned on an outsideof the object 26 (e.g., a housing), as shown in FIG. 1.

In the illustrated embodiment of FIG. 3, the retro-reflective marker 24is disposed on the outside of the person's clothing. For instance, theretro-reflective marker 24 may be applied as a strip of retro-reflectivetape applied to an armband, headband, shirt, personal identificationfeature, or other article. Additionally or alternatively, theretro-reflective marker 24 may, in some embodiments, be sewn intoclothing or applied to the clothing as a coating. The retro-reflectivemarker 24 may be disposed on the clothing of the person 70 in a positionthat is accessible to the electromagnetic radiation beam 28 beingemitted from the emitter 14. As the person 70 walks about the detectionarea 30 (in the case of the object 32, the object 32 may move throughthe area 30), the electromagnetic radiation beam 28 reflects off theretro-reflective marker 24 and back to the detector 16. The detector 16communicates with the control unit 18 by sending a signal 72 to theprocessor 20, this signal 72 being indicative of the reflectedelectromagnetic radiation detected via the detector 16. The trackingsystem 10 may interpret this signal 72 to track the position or path ofthe person 70 (or object 32) moving about a designated area (i.e., trackthe person or object in space and time). Again, depending on the numberof detectors 16 utilized, the control unit 18 may determine vectormagnitude, orientation, and sense of the person and/or object's movementbased on the retro-reflected electromagnetic radiation received.

The tracking of the person 70 (which may also be representative of amoving object) is illustrated schematically in FIG. 4. Morespecifically, FIG. 4 illustrates a series 80 of frames 82 captured bythe detector 16 (e.g., camera) over a period of time. As noted above, aplurality of such frames (e.g., between 30 and 60) may be generatedevery second in certain embodiments. It should be noted that FIG. 4 maynot be an actual representation of outputs produced by the trackingsystem 10, but is described herein to facilitate an understanding of thetracking and monitoring performed by the control unit 18. The frames 82each represent the detection area 30, and the position of theretro-reflective marker 24 within the area 30. Alternatively, the frames82 may instead represent marker blockage within the area 30, for examplewhere a grid of markers 24 are occluded by an object or person.

As shown, a first frame 82A includes a first instance of theretro-reflective marker, designated as 24A, having a first position. Asthe series 80 progresses in time, a second frame 82B includes a secondinstance of the retro-reflective marker 24B, which is displaced relativeto the first instance, and so on (thereby producing third and fourthinstances of the retro-reflective marker 24C and 24D). After a certainperiod of time, the control unit 18 has generated the series 80, wherethe operation of generating the series 80 is generally represented byarrow 84.

The series 80 may be evaluated by the control unit 18 in a number ofdifferent ways. In accordance with the illustrated embodiment, thecontrol unit 18 may evaluate movement of the person 70 or object 32 byevaluating the positions of the marker 24 (or blockage of certainmarkers) over time. For example, the control unit 18 may obtain vectororientation, range, and sense, relating to the movement of the trackedtarget depending on the number of detectors 16 utilized to perform thetracking. In this way, the control unit 18 may be considered to evaluatea composite frame 86 representative of the movement of the trackedretro-reflective marker 24 (or tracked blockage of markers 24) over timewithin the detection area 30. Thus, the composite frame 86 includes thevarious instances of the retro-reflective marker 24 (including 24A, 24B,24C, 24D), which may be analyzed to determine the overall movement ofthe marker 24 (and, therefore, the person 70 and/or object 26, whicheverthe case may be).

As also illustrated in FIG. 4, this monitoring may be performed relativeto certain environmental elements 88, which may be fixed within thedetection area 30 and/or may be associated with reflective materials.The control unit 18 may perform operations not only based on thedetected positions of the marker 24, but also based on extrapolatedmovement (e.g., a projected path of the retro-reflective marker 24through the detection area 30 or projected positions of marker gridocclusion) in relation to the environmental elements 88.

Another method for tracking one or more people 70 or objects 32 in anarea is illustrated schematically in FIG. 5. Specifically, FIG. 5represents an overhead view of a group of people 70 standing in thedetection area 30. Although not illustrated, the tracking system 10 maybe present directly above this detection area 30 in order to detectpositions of people 70 (and other objects) present within the detectionarea 30 (e.g., to obtain a plan view of the detection area 30). In theillustrated embodiment, the retro-reflective markers 24 are positionedin a grid pattern 90 on a floor 92 of the detection area 30 (e.g., as acoating, pieces of tape, or similar attachment method). Theretro-reflective markers 24 may be arranged in any desired pattern(e.g., grid, diamond, lines, circles, solid coating, etc.), which may bea regular pattern (e.g., repeating) or a random pattern.

This grid pattern 90 may be stored in the memory 22, and portions of thegrid pattern 90 (e.g., individual markers 24) may be correlated tolocations of certain environmental elements and amusement park features(e.g., the amusement park equipment 12). In this way, the position ofeach of the markers 24 relative to such elements may be known.Accordingly, when the markers 24 retro-reflect the electromagneticradiation beam 28 to the detector 16, the location of the markers 24that are reflecting may be determined and/or monitored by the controlunit 18.

As illustrated, when the people 70 or objects 32 are positioned over oneor more of the retro-reflective markers 24 on the floor 92, the occludedmarkers cannot reflect the emitted electromagnetic radiation back to thedetector 16 above the floor 92. Indeed, in accordance with anembodiment, the grid pattern 90 may include retro-reflective markers 24that are spaced apart by a distance that allows the people or objectspositioned on the floor 92 to be detectable (e.g., blocking at least oneof the retro-reflective markers 24). In other words, the distancebetween the markers 24 may be sufficiently small so that objects orpeople may be positioned over at least one of the retro-reflectivemarkers 24.

In operation, the detector 16 may function to detect the electromagneticradiation beam 28 retro-reflected from the retro-reflective markers 24that are not covered up by people or objects located in the detectionarea 30. As discussed above, the detector 16 may then provide dataassociated with this detection to the control unit 18 for processing.The control unit 18 may perform a comparison of the detectedelectromagnetic radiation beam reflected off the uncoveredretro-reflective markers 24 (e.g., a detected pattern) with storedpositions of the completely uncovered grid pattern 90 (e.g., a storedpattern) and/or other known grid patterns resulting from blockage ofcertain markers 24. Based on this comparison, the control unit 18 maydetermine which markers 24 are covered to then approximate locations ofthe people 70 or objects 32 within the plane of the floor 92. Indeed,the use of a grid positioned on the floor 92 in conjunction with asingle detector 16 may enable the tracking of movement in twodimensions. If higher order tracking is desired, additional grids and/oradditional detectors 16 may be utilized. In certain embodiments, basedon the locations of the people 70 or objects 32 in the detection area30, the control unit 18 may adjust the operation of the amusement parkequipment 12.

The process of emitting the electromagnetic radiation beam 28, sensingof the reflected electromagnetic radiation from the uncoveredretro-reflective markers 24 on the floor 92, and determining a locationof the people 70 may be performed by the control unit 18 numerous timesover a short period in order to identify a series of locations of thepeople 70 moving about the floor 92 (to track motion of the group).Indeed, such procedures may essentially be performed continuously tofacilitate identification of a path through which the people 70 havemoved within the detection area 30 during a particular timeframe orsimply in continuous series. Once the position or path one or more ofthe people 70 has been detected, the control unit 18 may further analyzethe position or path to determine whether any actions should beperformed by the equipment 12.

As discussed in detail above with respect to FIG. 1, the control unit 18may be configured to identify certain objects that are expected to crossthe path of the electromagnetic radiation beam 28 within the detectionarea 30, including objects that are not marked with retro-reflectivematerial. For example, as illustrated in FIG. 6, some embodiments of thetracking system 10 may be configured such that the control unit 18 isable to identify the person 70 (which is also intended to berepresentative of the object 32) located in the detection area 30,without the use of the retro-reflective markers 24. That is, the controlunit 18 may receive data indicative of the electromagnetic radiationreflected back from the detection area 30, and the control unit 18 maycompare a digital signature of the detected radiation to one or morepossible data signatures stored in memory 22. That is, if the signatureof electromagnetic radiation reflected back to the detector 16 matchesclosely enough to the signature of a person 70 or known object 32, thenthe control unit 18 may determine that the person 70 or object 32 islocated in the detection area 30. For example, the control unit 18 mayidentify “dark spots,” or regions where electromagnetic radiation wasabsorbed rather than reflected, within the detection area 30. Theseareas may have a geometry that the control unit 18 may analyze (e.g., bycomparing to shapes, sizes, or other features of stored objects orpeople) to identify a presence, location, size, shape, etc., of anobject (e.g., the person 70).

As may be appreciated with reference to FIGS. 1, 2, 3, and 6, thetracking system 10 may be positioned in a variety of locations to obtaindifferent views of the detection area 30. Indeed, it is now recognizedthat different locations and combinations of locations of one or more ofthe tracking systems 10 (or one or more elements of the tracking system10, such as multiple detectors 16) may be desirable for obtainingcertain types of information relating to the retro-reflective markers 24and the blockage thereof. For instance, in FIG. 1, the tracking system10, and in particular the detector 16, is positioned to obtain anelevational view of at least the object 26 fitted with theretro-reflective marker 24 and the object 32. In FIG. 2, the detector 16is positioned to obtain an overhead perspective view of the detectionarea 30, which enables detection of retro-reflective markers 24positioned on a variety of environmental elements, moving objects, orpeople. In the embodiments of FIGS. 3 and 6, the detector 16 may bepositioned to obtain a plan view of the detection area 30.

These different views may provide information that may be utilized bythe control unit 18 for specific types of analyses and, in certainembodiments, control actions that may depend on the particular settingin which they are located. For example, in FIG. 7, the tracking system10, and particularly the emitter 14 and the detector 16, are positionedto obtain a perspective view of the person 70 (or object 32) in thedetection area 30. The detection area 30 includes the floor 92, but alsoincludes a wall 93 on which the retro-reflective markers 24 arepositioned to form the grid pattern 90. Here, the person 70 is blockinga subset of markers 24 positioned on the wall 93. The subset of markers24 are unable to be illuminated by the emitter 14, are unable toretro-reflect the electromagnetic radiation back to the detector 16, orboth, because the person 70 (also intended to represent an object) ispositioned between the subset of markers 24 and the emitter 14 and/ordetector 16.

The grid pattern 90 on the wall 93 may provide information notnecessarily available from a plan view as shown in FIGS. 3 and 6. Forexample, the blockage of the retro-reflective markers 24 enables thecontrol unit 18 to determine a height of the person 70, a profile of theperson 70, or, in embodiments where there the object 32 is present, asize of the object 32, a profile of the object 32, and so forth. Suchdeterminations may be made by the control unit 18 to evaluate whetherthe person 70 meets a height requirement for a ride, to evaluate whetherthe person 70 is associated with one or more objects 32 (e.g., bags,strollers), and may also be used to track movement of the person 70 orobject 32 through the detection area 30 with a greater degree ofaccuracy compared to the plan view set forth in FIGS. 3 and 6. That is,the control unit 18 is better able to tie movement identified byblockage of the markers 24 to a particular person 70 by determining theperson's profile, height, etc. Similarly, the control unit 18 is betterable to track the movement of the object 32 through the detection area30 by identifying the geometry of the object 32, and tying identifiedmovement specifically to the object 32. In certain embodiments, trackingthe height or profile of the person 70 may be performed by the trackingsystem 10 to enable the control unit 18 to provide recommendations tothe person 70 based on an analysis of the person's evaluated height,profile, etc. Similar determinations and recommendations may be providedfor objects 32, such as vehicles. For example, the control unit 18 mayanalyze a profile of guests at an entrance to a queue area for a ride.The control unit 18 may compare the overall size, height, etc., of theperson 70 with ride specifications to warn individuals or provide aconfirmation that they are able to ride the ride before spending time inthe queue. Similarly, the control unit 18 may analyze the overall size,length, height, etc., of a vehicle to provide parking recommendationsbased on available space. Additionally or alternatively, the controlunit 18 may analyze the overall size, profile, etc., of an automatedpiece equipment before allowing the equipment to perform a particulartask (e.g., movement through a crowd of people).

The pattern 90 may also be positioned on both the wall 93 and the floor92. Accordingly, the tracking system 10 may be able to receiveretro-reflected electromagnetic radiation from markers 24 on the wall 93and the floor 92, thereby enabling detection of marker blockage andmonitoring of movement in three dimensions. Specifically, the wall 93may provide information in a height direction 94, while the floor 92 mayprovide information in a depth direction 96. Information from both theheight direction 94 and the depth direction 96 may be correlated to oneanother using information from a width direction 98, which is availablefrom both the plan and elevational views.

Indeed, it is now recognized that if two objects 32 or people 70 overlapin the width direction 98, they may be at least partially resolved fromone another using information obtained from the depth direction 96.Further, it is also now recognized that the use of multiple emitters 14and detectors 16 in different positions (e.g., different positions inthe width direction 98) may enable resolution of height and profileinformation when certain information may be lost or not easily resolvedwhen only one emitter 14 and detector 16 are present. More specifically,using only one emitter 14 and detector 16 may result in a loss ofcertain information if there is overlap between objects 32 or people 70in the width direction 98 (or, more generally, overlap in a directionbetween the markers 24 on the wall 93 and the detector 16). However,embodiments using multiple (e.g., at least two) detectors 16 and/oremitters 14 may cause distinct retro-reflective patterns to be producedby the markers 24 and observed from the detectors 16 and/or emitters 14positioned at different perspectives. Indeed, because the markers 24 areretro-reflective, they will retro-reflect electromagnetic radiation backtoward the electromagnetic radiation source, even when multiple sourcesemit at substantially the same time. Thus, electromagnetic radiationemitted from a first of the emitters 14 from a first perspective will beretro-reflected back toward the first of the emitters 14 by the markers24, while electromagnetic radiation emitted from a second of theemitters 14 at a second perspective will be retro-reflected back towardthe second of the emitters 14 by the markers 24, which enables multiplesets of tracking information to be produced and monitored by the controlunit 18.

It is also now recognized that the retro-reflective markers 24 on thewall 93 and the floor 92 may be the same, or different. Indeed, thetracking system 10 may be configured to determine which electromagneticradiation was reflected from the wall 93 versus which electromagneticradiation was reflected from the floor 92 using a directionality of theretro-reflected electromagnetic radiation from the wall 93 and the floor92. In other embodiments, different materials may be used for themarkers 24 so that, for example, different wavelengths ofelectromagnetic radiation may be reflected back toward the emitter 14and detector 16 by the different materials. As an example, theretro-reflective markers 24 on the floor 92 and the wall 93 may have thesame retro-reflective elements, but different layers that act to filteror otherwise absorb portions of the emitted electromagnetic radiation sothat electromagnetic radiation reflected by the retro-reflective markers24 on the floor 92 and wall 93 have characteristic and differentwavelengths. Because the different wavelengths would be retro-reflected,the detector 16 may detect these wavelengths and separate them fromambient electromagnetic radiation, which is filtered by filter elementswithin the detector 16.

To help illustrate, FIG. 8 depicts expanded cross-sectional views ofexample retro-reflective markers 24 disposed on the floor 92 and thewall 93 within the detection area 30. The markers 24 on the floor 92 andthe wall 93 each include a reflective layer 96 and a retro-reflectivematerial layer 98, which may be the same or different for the floor 92and wall 93. In the illustrated embodiment, they are the same. Duringoperation, electromagnetic radiation emitted by the emitter 14 maytraverse a transmissive coating 99 before striking the retro-reflectivematerial layer 98. Accordingly, the transmissive coating 99 may be usedto adjust the wavelengths of electromagnetic radiation that areretro-reflected by the markers. In FIG. 8, the markers 24 on the floor92 include a first transmissive coating 99A, which is different than asecond transmissive coating 99B in the markers 24 on the wall 93. Incertain embodiments, different optical properties between the first andsecond transmissive coatings 99A, 99B may cause a different bandwidth ofelectromagnetic radiation to be reflected by the markers 24 on the floor92 and the markers 24 on the wall 93. While presented in the context ofbeing disposed on the floor 92 and the wall 93, it should be noted thatmarkers 24 having different optical properties may be used on a varietyof different elements within the amusement park, such as on people andenvironmental elements, people and moving equipment, and so on, tofacilitate separation for processing and monitoring by the control unit18.

Any one or a combination of the techniques set forth above may be usedto monitor a single object or person, or multiple objects or people.Indeed, it is presently recognized that a combination of multipleretro-reflective marker grids (e.g., on the floor 92 and wall 93 as setforth above), or a combination of one or more retro-reflective markergrids and one or more tracked retro-reflective markers 24 fixed on amovable object or person, may be utilized to enable three-dimensionaltracking, even when only one detector 16 is utilized. Further, it isalso recognized that using multiple retro-reflective markers 24 on thesame person or object may enable the tracking system 10 to track bothposition and orientation.

In this regard, FIG. 9A illustrates an embodiment of the object 26having multiple retro-reflective markers 24 positioned on differentfaces of the object 26. Specifically, in the illustrated embodiment, theretro-reflective markers 24 are disposed on three different points ofthe object 26 corresponding to three orthogonal directions (e.g., X, Y,and Z axes) of the object 26. However, it should be noted that otherplacements of the multiple retro-reflective markers 24 may be used inother embodiments. In addition, the tracking depicted in FIG. 9A may beperformed as generally illustrated, or may also utilize a grid of theretro-reflective markers 24 as shown in FIG. 7.

As noted above, the tracking system 10 may include multiple detectors 16configured to sense the electromagnetic radiation that is reflected backfrom the object 26, for example. Each of the retro-reflective markers 24disposed on the object 26 may retro-reflect the emitted electromagneticradiation beam 28 at a particular, predetermined frequency of theelectromagnetic spectrum of the electromagnetic radiation beam 28.

That is, the retro-reflective markers 24 may retro-reflect the same ordifferent portions of the electromagnetic spectrum, as generally setforth above with respect to FIG. 8.

The control unit 18 is configured to detect and distinguish theelectromagnetic radiation reflected at these particular frequencies and,thus, to track the motion of each of the separate retro-reflectivemarkers 24. Specifically, the control unit 18 may analyze the detectedlocations of the separate retro-reflective markers 24 to track the roll(e.g., rotation about the Y axis), pitch (e.g., rotation about the Xaxis), and yaw (e.g., rotation about the Z axis) of the object 26. Thatis, instead of only determining the location of the object 26 in spacerelative to a particular coordinate system (e.g., defined by thedetection area 30 or the detector 16), the control unit 18 may determinethe orientation of the object 26 within the coordinate system, whichenables the control unit 18 to perform enhanced tracking and analyses ofthe movement of the object 26 in space and time through the detectionarea 30. For instance, the control unit 18 may perform predictiveanalyses to estimate a future position of the object 26 within thedetection area 30, which may enable enhanced control over the movementof the object 26 (e.g., to avoid collisions, to take a particular paththrough an area).

In certain embodiments, such as when the object 26 is a motorizedobject, the tracking system 10 may track the position and orientation ofthe object 26 (e.g., a ride vehicle, an automaton, an unmanned aerialvehicle) and control the object 26 to proceed along a path in apredetermined manner. The control unit 18 may, additionally oralternatively, compare the results to an expected position andorientation of the object 26, for example to determine whether theobject 26 should be controlled to adjust its operation, and/or todetermine whether the object 26 is operating properly or is in need ofsome sort of maintenance. In addition, the estimated position andorientation of the object 26, as determined via the tracking system 10,may be used to trigger actions (including preventing certain actions) byother amusement park equipment 12 (e.g., show effects). As one example,the object 26 may be a ride vehicle and the amusement park equipment 12may be a show effect. In this example, it may be desirable to onlytrigger the amusement park equipment 12 when the object 26 is in theexpected position and/or orientation.

Continuing with the manner in which tracking in three spatial dimensionsmay be preformed, FIG. 9B depicts an example of the object having afirst marker 24A, a second marker 24B, and a third marker 24C positionedin similar positions as set forth in FIG. 9A. However, from theperspective of a single one of the detectors 16, the detector 16 may seea two-dimensional representation of the object 16, and the markers 24A,24B, 24C. From this first perspective (e.g., overhead or bottom view),the control unit 18 may determine that the first and second markers 24A,24B are separated by a first observed distance d1, the first and thirdmarkers 24A, 24C are separated by a second observed distance d2, and thesecond and third markers 24B, 24C are separated by a third observeddistance d3. The control unit 18 may compare these distances to known orcalibrated values to estimate an orientation of the object 26 in threespatial dimensions.

Moving to FIG. 9C, as the object 26 rotates, the detector 16 (and,correspondingly, the control unit 18) may detect that the apparent shapeof the object 26 is different. However, the control unit 18 may alsodetermine that the first and second markers 24A, 24B are separated by anadjusted first observed distance d1′, the first and third markers 24A,24C are separated by an adjusted second observed distance d2′, and thesecond and third markers 24B, 24C are separated by an adjusted thirdobserved distance d3′. The control unit 18 may determine a differencebetween the distances detected in the orientation in FIG. 9B and thedistances detected in the orientation in FIG. 9C to determine how theorientation of the object 26 has changed to then determine theorientation of the object 26. Additionally or alternatively, the controlunit 18 may compare the adjusted observed distances d1′, d2′, d3′resulting from rotation of the object 26 to stored values to estimate anorientation of the object 26 in three spatial dimensions, or to furtherrefine an update to the orientation determined based on the changebetween the distances in FIGS. 9B and 9C.

As set forth above, present embodiments are directed to, among otherthings, the use of the disclosed tracking system 10 to track objectsand/or people within an amusement park environment. As a result of thistracking, the control unit 18 may, in some embodiments, cause certainautomated functions to be performed within various subsystems of theamusement park. Accordingly, having described the general operation ofthe disclosed tracking system 10, more specific embodiments of trackingand control operations are provided below to facilitate a betterunderstanding of certain aspects of the present disclosure.

Moving now to FIG. 10, an embodiment of a method 100 of monitoringchanges in reflected electromagnetic radiation to track movement of atarget and control amusement park equipment as result of this monitoringis illustrated as a flow diagram. Specifically, the method 100 includesthe use of one or more of the emitters 14 (e.g., an emission subsystem)to flood (block 102) the detection area 30 with electromagneticradiation (e.g., electromagnetic radiation beam 28) using the emissionsubsystem. For instance, the control unit 18 may cause one or more ofthe emitters 14 to intermittently or substantially continuously floodthe detection area 30 with emitted electromagnetic radiation. Again, theelectromagnetic radiation may be any appropriate wavelength that is ableto be retro-reflected by the retro-reflective markers 24. This includes,but is not limited to, ultraviolet, infrared, and visible wavelengths ofthe electromagnetic spectrum. It will be appreciated that differentemitters 14, and in some embodiments, different markers 24, may utilizedifferent wavelengths of electromagnetic radiation to facilitatedifferentiation of various elements within the area 30.

After flooding the detection area 30 with electromagnetic radiation inaccordance with the acts generally represented by block 102, the method100 proceeds to detecting (block 104) electromagnetic radiation that hasbeen reflected from one or more elements in the detection area 30 (e.g.,the retro-reflective markers 24). The detection may be performed by oneor more of the detectors 16, which may be positioned relative to theemitter 14 as generally set forth above with respect to FIGS. 1 and 2.As described above and set forth in further detail below, the featuresthat perform the detection may be any appropriate element capable of andspecifically configured to capture retro-reflected electromagneticradiation and cause the captured retro-reflective electromagneticradiation to be correlated to a region of the detector 16 so thatinformation transmitted from the detector 16 to the control unit 18retains position information regarding which of the markers 24 reflectedelectromagnetic radiation to the detector 16. As one specific butnon-limiting example, one or more of the detectors 16 (e.g., present asa detection subsystem) may include charge coupled devices within anoptical camera or similar feature.

As described above, during the course of operation of the trackingsystem 10, and while people 70 and/or objects 26, 32 are present withinthe detection area 30, it may be expected that changes in reflectedelectromagnetic radiation will occur. These changes may be tracked(block 106) using a combination of the one or more detectors 16 androutines performed by processing circuitry of the control unit 18. Asone example, tracking changes in the reflected electromagnetic radiationin accordance with the acts generally represented by block 106 mayinclude monitoring changes in reflected patterns from a grid over acertain period of time, monitoring changes in spectral signaturespotentially caused by certain absorptive and/or diffusively orspecularly reflective elements present within the detection area 30, orby monitoring certain moving retro-reflective elements. As describedbelow, the control unit 18 may be configured to perform certain types oftracking of the changes in reflection depending on the nature of thecontrol to be performed in a particular amusement park attractionenvironment.

At substantially the same time or shortly after tracking the changes inreflected electromagnetic radiation in accordance with the actsgenerally represented by block 106, certain information may be evaluated(block 108) as a result of these changes by the control unit 18. Inaccordance with one aspect of the present disclosure, the evaluatedinformation may include information pertaining to one or moreindividuals (e.g., amusement park guests, amusement park employees) toenable the control unit 18 to monitor movement and positioning ofvarious individuals, and/or make determinations relating to whether theperson is appropriately positioned relative to certain amusement parkfeatures. In accordance with another aspect of the present disclosure,the information evaluated by the control unit 18 may include informationrelating to objects 26, 32, which may be environmental objects, movingobjects, the amusement park equipment 12, or any other device, item, orother feature present within the detection area 30. Further detailsregarding the manner in which information may be evaluated is describedin further detail below with reference to specific examples of amusementpark equipment controlled at least in part by the control unit 18.

As illustrated, the method 100 also includes controlling (block 110)amusement park equipment based on the information (e.g., monitored andanalyzed movement of people and/or objects) evaluated in accordance withacts generally represented by block 108. It should be noted that thiscontrol may be performed in conjunction with concurrent tracking andevaluation to enable the control unit 18 to perform many of the stepsset forth in method 100 on a substantially continuous basis and inreal-time (e.g., on the order of the rate of capture of the detector16), as appropriate. In addition, the amusement park equipmentcontrolled in accordance with the acts generally represented by block110 may include automated equipment such as ride vehicles, access gates,point-of-sale kiosks, informational displays, or any other actuatableamusement park device. As another example, the control unit 18 maycontrol certain show effects such as the ignition of a flame or afirework as a result of the tracking and evaluation performed inaccordance with method 100. More details relating to certain of thesespecific examples are described in further detail below.

In accordance with a more particular aspect of the present disclosure,the present embodiments relate to the tracking of retro-reflectivemarkers positioned on certain environmental and functional features ofan amusement park attraction area using survey equipment. For example,in certain embodiments, park equipment may be monitored for degradationdue to mechanical and/or environmental stresses. Using this information,the control unit 18 may provide information relating to the currentstate of the particular equipment and, in some embodiments, may providerecommendations for maintenance or other procedures. More specifically,the amusement park equipment 12 may include various systems configuredto provide such information to ride operators, facilities engineers, andso forth. For example, the amusement park equipment 12 that may becontrolled in relation to surveying certain amusement park features mayinclude displays, report-generating features, and the like.

In the specific context of an amusement park, the tracking system 10 maybe disposed in surveying equipment 140, as illustrated in FIG. 11, todetermine a variety of maintenance-related information relating toroller coasters or similar rides, and/or relating to facilities housingcertain amusement attraction features. In the illustrated embodiment,the surveying equipment 140 outputs the electromagnetic radiation beam28 with a relatively large range to capture data representative ofseveral different components in its field of view at the same time.These components may include, for example, supports 142 (e.g., ridecolumn) of a roller coaster 144, building structures 146, and any otherstructures that may be in the field of view of the tracking system 10within the surveying equipment 140. Any number of these components maybe equipped with one or more of the retro-reflective markers 24.

In the illustrated embodiment, certain of the retro-reflective markers24 are disposed on each of the supports 142 and the building structure146. The surveying equipment 140 may survey this series ofretro-reflective markers 24 nearly instantaneously, since they are allwithin the field of view of the tracking system 10. As described infurther detail below, by evaluating the detected locations (bothindividual and in reference to each other) of the retro-reflectivemarkers 24, it may be possible to determine whether settlement of any ofthese supports 142 or the building structure 146 has occurred over time.In addition, since the surveying equipment 140 can take readings ofmultiple such retro-reflective markers 24 at the same time via thetracking system 10, this may reduce the amount of time it takes tosurvey the area.

In accordance with a further embodiment, the tracking system 10 in thesurveying equipment 140 may be used to determine whether a spectralshift has occurred over time on building structures 146 or otherstructures that have been painted. Specifically, the surveying equipment140 may be used early on, when the building structure 146 has just beenpainted, to determine an amount of electromagnetic radiation reflectedfrom the newly painted building structure 146. At a later point in time,the surveying equipment 140 may be used to detect the electromagneticradiation reflected from the building structure 146, compare thisreflected signature to the previously stored data, and determine whetherspectral shift (e.g., paint fading) has occurred and if the buildingstructure 146 should be repainted.

As also illustrated, the surveying equipment 140, and specifically thetracking system 10, may, in certain embodiments, be in communicationwith a diagnostic system 150. In still further embodiments, thediagnostic system 150 may be integrated as a part of the surveyingequipment 140 and/or implanted within the tracking system 10 (e.g., as apart of the control unit 18). As one example, the tracking system 10 mayobtain tracking data relating to the retro-reflective markers 24 and/orother optically detectable features of the building 146 and/or ride 144.The tracking system 10 may provide this information to the diagnosticsystem 150, which may include processing circuitry 152 such as one ormore processors configured to execute diagnostic routines stored on amemory of the system 150. The memory may also include legacy informationrelating to prior analyses performed on the building 146 and ride 144,so that the state of these features may be tracked and compared overtime.

The diagnostic system 150 may also include an information system 154 incommunication with the surveying equipment 140 and the processingcircuitry 152. The information system 154 may include various userinterface features 156, such as one or more displays 158 and/or one ormore report generation features 160. The user interface features 156 maybe configured to provide users (e.g., operators, facilities engineers)with perceivable indicators relating to the evaluated health of thesurveyed features and/or to provide the monitored data to the users toenable the users to analyze the data directly. However, it is within thescope of the present disclosure for the tracking system 10, thesurveying equipment 140, and/or the diagnostic system 150 to analyze andinterpret the monitored data to provide an indication to the usersrelating to whether the tracked amusement park feature is in need ofmaintenance.

Another example of the manner in which the surveying system 140 may beutilized in the context of evaluating a paint color and/or surfaceintegrity of the building 146 is depicted in FIG. 12. Specifically, FIG.12 depicts a portion 170 of the building 146 at different time points.The different time points of the building 146 may be considered torepresent, by way of example, the effect of time as well asenvironmental stresses on the building 146. FIG. 12, as illustrated,includes the portion 170 at a first time point of the building 146,which is represented as 146A.

As shown at the first time point of the building 146A, the portion 170includes one of the retro-reflective markers 24 disposed underneath asurface treatment 172. At the first time point, these are represented asportion 170A and surface treatment 172A. The surface treatment 172 mayinclude, by way of example, a coating (e.g., paint) or a covering (e.g.,brick, stucco). As shown, over time and upon exposure to variousenvironmental stresses (e.g., weather, sunlight), the first surfacetreatment 172A begins to fade, thin, crack, peel, or otherwise degradeto a second surface treatment 172B (a degraded version of the firstsurface treatment 172A), which results in a portion 174 of theretro-reflective marker 24 being exposed.

The surveying equipment 140, and specifically the tracking system 10,may recognize this change by determining that the retro-reflectivemarker 24 is able to receive and retro-reflect the electromagneticradiation emitted by the emitter 14 of the tracking system 10. Thediagnostic system 150 may be configured to determine the degree to whichthe retro-reflective marker 24 has become exposed by, for example,tracking the intensity of the retro-reflected electromagnetic radiationand comparing the intensity to a stored intensity, pattern, etc. Thediagnostic system 150 may also use the degree to which theretro-reflective marker 24 has become exposed to evaluate a relativedegree of degradation of the surface treatment 172.

As also illustrated, the portion 170 may also progress to a thirdportion 170C having a third surface treatment 172C (a further degradedversion of the second surface treatment 172B), where theretro-reflective marker 24 has become fully exposed. In such asituation, the tracking system 10 may recognize that theretro-reflective marker 24 has become fully exposed and may cause theinformation system 160 to provide a user-perceivable indication that thesurface treatment 170C may need to be re-applied or otherwise repaired.

In accordance with an aspect of the present disclosure, the surveyingequipment 140 may, additionally or alternatively, be used to monitor aposition of certain amusement park structural features, such as thesupports 142 and/or a track 180 supported by the supports 142 as shownin FIG. 13. For example, over time, the supports 142 may settle into theground 182, and it may be desirable to recognize and/or monitor thissettling over time to determine whether maintenance may be required onthe ride 144. Also, the track 180 on the supports 142 may also shift itsposition over time, for example by sagging or shifting horizontally dueto gravity, use (e.g., vibrations), and other factors.

One or more of the retro-reflective markers 24 may be positioned on thesupports 142, the track 180, and/or on the ground 182 (which maycorrespond to the floor 92 if the ride 144 is an indoor attraction). Theretro-reflective markers 24 may be positioned on the supports 142 andthe track 180 in regions where movement, degradation, sagging, settling,etc., is recognizable and/or most likely to occur. For example, asillustrated in FIG. 13, a plurality of retro-reflective markers 24 arepositioned along a longitudinal axis of the supports 142, while one ofthe retro-reflective markers 24 is positioned on a portion of the track180 between the supports 142, where settling or sagging might be mostlikely to occur.

The survey equipment 140 may, accordingly, identify a position of thesemarkers 24 relative to a position of a certain environmental feature,such as the ground. The survey equipment 140 may include any number offeatures configured to perform surveying techniques and, indeed, thetracking system 10 of the present disclosure may simply be used inconjunction with such features, or in place of at least some of thesefeatures. By way of example, the survey equipment 140 may include anynumber of survey equipment features known in the art, such as a totalstation, a robotic total station, an electronic distance meter, atheodolite, or any combination of these or similar features.Furthermore, the control unit 18 may include or otherwise be incommunication with various surveying circuitry 184, including (but notlimited to) distance analysis circuitry 186 and/or angle analysiscircuitry 188 compatible with, for example, distance meters andtheodolites.

As one non-limiting example, all or a part of the tracking system 10,including the retro-reflective markers 24, may be used in combinationwith electronic distance measurement techniques to evaluate shifting ofthe different features of the ride 144. For instance, electronicdistance measurement may generally be performed based on the emission oflight, the detection of light reflected from a target, and themeasurement of the phase difference between the emitted and reflectedlight. The phase difference can be used to determine the distance of thereflecting target from the emission source. Typically, one measurementwould be performed at a time. However, in accordance with presentembodiments, the detector 16 may be configured to capture multiplesignals from multiple reflecting targets (i.e., multipleretro-reflective markers 24) without a loss of phase information.Accordingly, it is now recognized that the disclosed tracking system 10may be integrated with existing surveying equipment and methodology togreatly enhance the speed by which survey measurement may be performed.It should be noted that equipment in accordance with present embodimentsmay also monitor vibration (e.g., slight shifts in equipment) duringoperation of the monitored system (e.g., a roller coaster). This mayfacilitate identification of components of the system (e.g., tracksegments) subject to increased wear.

As an example of the manner in which the tracking system 10 may beintegrated with electronic distance measurement survey equipment tomonitor shifting or excessive vibration of the ride 144, the emitter 14may emit the electromagnetic radiation beam 28 into the detection area30 including the supports 142 and track 180. The emission may bemodulated using, for example, a quartz crystal oscillator that acts asan electronic shutter. The phase of the emitted electromagneticradiation is, therefore, established by the system in accordance withpresent techniques.

The detector 16 may then capture and record the retro-reflectedelectromagnetic radiation from the retro-reflective markers 24 atsubstantially the same time. That is, the detector 16 may record boththe source and the phase of the retro-reflected electromagneticradiation from all of the retro-reflective markers 24 at once. Thisinformation may be provided to the surveying circuitry 184, which maycompare the measured phase to the known phase of the emitted radiation.The distance to the retro-reflective markers 24 may then be calculatedbased, at least in part, on the difference in phase between thetransmitted and the received electromagnetic radiation.

The calculated distances for the retro-reflective markers on thesupports 142 may be compared to the markers 24 on the track 180 toidentify, for instance, movement of the track 180 relative to thesupports 142 (assuming that the markers 24 were positioned for a priormeasurement for comparative or baseline purposes, and the markers 24 arein the same position). Settling of the supports 142 may be identified,for instance, based on changing distances between the ground (on which areflector may be positioned, as shown), and the measuredretro-reflective markers 24 on the supports 142. The supports 142 mayalso be measured relative to one another to identify whether one of thesupports 142 might have moved relative to another, which could affectthe track 180. As set forth above with respect to FIG. 11, theinformation obtained from these types of surveys may be relayed to theinformation system 154 to enable a technician to address any potentialissues with the surveyed equipment.

In addition to or as an alternative to monitoring the structural healthof various amusement park equipment, the presently disclosed trackingsystem 10 may also be used to track pyrotechnic show effects produced byvarious equipment and, if appropriate, adjust the equipment producingthe pyrotechnic show effects. Such tracking and control may be applied,for example, to the production of a flame effect, to a firework show, orother setting. FIG. 14 illustrates an example of how the tracking system10 may be used to identify and/or monitor a flame effect 200 (or someother heating effect). The flame effect 200 may be a part of anamusement park attraction such as a ride, a stunt show, or any otherapplication where it is desirable to regularly provide a controlledflame. The flame effect 200 may, in certain embodiments, correspond tothe production of a pattern of burning material, such as in a firework.

As discussed above with reference to FIG. 1, the control unit 18 of thetracking system 10 may be able to identify an object in the detectionarea 30 of the tracking system 10, without the use of theretro-reflective markers 24. That is, the control unit 18 may receivedata indicative of the electromagnetic radiation reflected back from thedetection area 30, and the control unit 18 may compare the signature ofthe reflected radiation to one or more possible data signatures storedin memory 22. In some embodiments, the control unit 18 may include athermal signature stored in the memory 22, this thermal signaturecorresponding to the light from the flame effect 200 that is expected toreach the detector 16 when the flame effect 200 is operating properly.This thermal signature may be generated and stored in the memory 22 byrepeatedly testing the flame effect 200 and averaging theelectromagnetic radiation detected via the detector 16 over thosemultiple tests. Then, when the ride is operating, the control unit 18may compare a thermal signature of detected electromagnetic radiation202 from the flame effect 200 with the thermal signature stored in thememory 22.

The control unit 18 may trigger one or more pyrotechnic show effectsbased on a comparison made between the actual thermal signature detectedvia the detector 16 and the expected thermal signature. Specifically, ifthe thermal signature detected via the detector 16 is not approximatelythe same (e.g., within certain constraints) as the expected flame effectstored in the memory 22, the control unit 18 may signal the amusementpark equipment 12 to notify a ride operator that the flame effect 200 isnot functioning correctly, to actuate a sprinkler system within the ridearea, to shut down the ride, and/or to stop the flame effect 200altogether. Depending on whether the detected thermal signature is muchlarger or smaller than the desired thermal signature, one or more ofthese effects may be triggered via the control unit 18.

It should be noted that the same tracking system 10 (e.g., emitter 14and detector 16) may simultaneously monitor both the flame effect 200and other portions of the ride. For example, in the illustratedembodiment, the tracking system 10 is positioned to detect both thethermal signature of electromagnetic radiation from the flame effect 200and a position of a ride vehicle 204 moving along the track 180. To thatend, the ride vehicle 204 may include one or more retro-reflectivemarkers 24 disposed thereon for tracking the motion of the ride vehicle204 via the same tracking system 10 that monitors the flame effect 200,as long as the frequency of light reflected by the retro-reflectivemarker 24 is distinguishable from the flame effect signature. Due to thetracking system's ability to detect the retro-reflective marker 24 evenin the presence of electromagnetic radiation including the wavelengthsemitted by the emitter 14, the electromagnetic radiation from the flameeffect 200 does not prevent the control unit 18 from identifying andlocating the retro-reflective marker 24 on the ride vehicle 204. Thus,one tracking system 10 may be used to accomplish what wouldtraditionally be accomplished using two or more distinct andfunctionally different detection systems, one for the flame effect 200and another for the ride vehicle 204. Similar techniques may be appliedin other contexts where it is desirable to detect a location of oneobject located near a flame effect (or some other bright effect) (e.g.,an ordinance during a firework display).

FIG. 15 illustrates an embodiment of the flame effect 200 and the mannerin which the tracking system 10 may be used to control and adjust theoperation of the flame effect 200. Specifically, the flame effect 200includes a flame-producing device 210, which includes a nozzle 212configured to mix a fuel provided from a fuel source 214 and an oxidantprovided from an oxidant source 216. The nozzle 212 may have arespective fuel inlet 218 and a respective oxidant inlet 220 configuredto receive the fuel and the oxidant into the nozzle 212. These mayconstitute the inlets of the flame-producing device 210, or may beseparate from the inlets thereof.

The flame-producing device 210 also includes a combustion chamber 222,where the mixed fuel and oxidant are ignited using an ignition source224 (e.g., one or more spark plugs). The combustion produces a flame226, which protrudes from an outlet 228 of the flame-producing device210. One or more flame additives from a flame additive source 230 may beadded to the flame 226 to adjust the color of the flame 226. Forexample, the flame additives may include metal salts, which may changethe color of the flame 226 from orange and red to blue, green etc.

The control unit 18, using one or more of the detectors 16, may monitorthe optical qualities of the flame 226 and, as a result of thismonitoring, may perform certain control actions to adjust the flame 226as appropriate. For example, the control unit 18 may be communicativelycoupled to any one or a combination of the fuel source 214, oxidantsource 216, ignition source 214, and flame additive source 230 to adjustthe flame 226. As also illustrated, control unit 18 may include flameanalysis circuitry 232, including flame shape analysis circuitry 234configured to analyze a shape of the flame 226, flame timing analysiscircuitry 236 configured to analyze a timing of the flame 226, and flamecolor analysis circuitry 238 configured to analyze the colors of theflame 226. The control unit 18, as an example, may control an amount offuel and/or oxidant provided to the nozzle 212 by controlling the fueland/or oxidant sources 214, 216. Similarly, the control unit 18 maycontrol the timing of the flame 226 by adjusting the ignition source224, and may adjust a color of the flame 226 by adjusting a flameadditive provided by the flame additive source 230 (e.g., an amount ofthe additive) and/or the fuel source 214 (e.g., a flow of the fuel)and/or the oxidant source 216 (e.g., a flow of the oxidant).

Similar applications exist for equipment incorporating the trackingsystem 10 disclosed herein. For example, as illustrated in FIG. 16, thetracking system 10 may be used to control a firework (or ordinance) show240 performed in a pyrotechnic show area, for example to enable enhancedmonitoring and control of firework timing. Indeed, the tracking system10 may use aspects relating to surveying (e.g., distance measurement) aswell as flame monitoring in controlling the firework show 240. Sincethere may inherently be some variability between how long after a fuseis lit before the individual ordinance will ignite and explode as afirework, as well as how high the ordinance has traveled upward prior toignition, it is now recognized that more accurate systems forcontrolling the height at which these ordinances reach before ignitionis desired. This may produce a more consistent show.

In accordance with present embodiments, the tracking system 10 may beused to detect and track an ordinance 242 as it travels upward throughthe air. The tracking system 10 may send a signal indicative of theheight of the ordinance above the ground 182 to a remote detonationsystem 244, which may communicate wirelessly with a detonator in theordinance 242. When the ordinance 242 reaches a desirable height 246above the ground, the remote detonation system 244 may send a wirelesssignal to the detonator in the ordinance 242 to initiate ignition andexplosion of the ordinance 242 at approximately the desired height 246.

FIG. 17 illustrates an example embodiment of the ordinance 242 and themanner in which the tracking system 10 may track the ordinance 242during flight. As illustrated in FIG. 17, the ordinance 242 includes anouter casing 260 enclosing various features of the ordinance 242. Incertain embodiments, the internal features include a fuse 262 (whichalso extends out of the casing 260), which is lit and is used to ignitea lift charge 264. The lift charge 264 is typically responsible for theheight that the ordinance 242 will reach in the air. However, as setforth below, the ordinance 242 may be launched using other features,such as compressed air. Accordingly, the ordinance 242 may not includethe fuse 262. The presently disclosed ordinance 242 may includeelectronic detonator features (e.g., an electronic fuse mechanism), suchas an electronic detonator 266 and a transceiver 268 configured toreceive detonation signals from the remote detonation system 244. Theordinance 242 may include an internal fuse 270 connected to theelectronic detonator 266, or a standalone fuse 271 coupled to the liftcharge 264. The electronic detonator 266 may be configured to ignite aburst charge 272 via the internal fuse 270. However, other embodimentsmay utilize the standalone fuse 271 that is not coupled to an electronicfeature for detonation. The burst charge 272 causes a plurality ofpyrotechnic features (pyrotechnic show elements) commonly referred to as“stars” 274, to be released and burned. Typically, the stars 274 includea mixture of metal salts that, when burned, produce color.

As also illustrated, one or more of the retro-reflective markers 24 maybe positioned on the outer casing 260. The marker 24 may enable thetracking system 10 to track the ordinance 242 after the lift charge 264is ignited and while the ordinance 242 is in the air. For example, theemitter 14 and the detector 16 may be positioned on the building 146,and the detector 16 may track the marker 24 through the flight of theordinance 242 to determine how high the ordinance 242 was before itburst. The triggering of the pyrotechnic show elements may be detectedby the control unit 18, for example, by detecting a pattern ofelectromagnetic radiation associated with the pyrotechnic show elements(the stars 274) stored in the memory 22. The control unit 18 may beconfigured to determine a location at which the ordinance 242 detonatedbased on the detected triggering of the pyrotechnic show elements.Additionally or alternatively, the control unit 18 may track themovement of the ordinance 242 through the air (i.e., track itstrajectory), and identify a triggering event of the ordinance 242(detonation of the ordinance 242) when the retro-reflective marker 24 onthe enclosure 260 is no longer visible to the detector 16 (e.g.,termination of the retro-reflection by the retro-reflective marker 24 isassociated with detonation of the ordinance 242).

Additionally or alternatively, the control unit 18, using routinesstored in memory 22 and executed by processor 20, may track theordinance 242 and relay instructions to the remote detonation system 244to initiate detonation of the ordinance 242. Specifically, the remotedetonation system 244 may include processing circuitry such as one ormore processors 280 configured to, using instructions stored in one ormore memory 282, interpret signals (e.g., data, instructions) from thecontrol unit 18. As a result, the remote detonation system 244 may sendwireless control signals from a transceiver 284 and to the respectivetransceiver 268 of the ordinance 242 to initiate detonation using thedetonation electronics. As one example, the control unit 18 may provideeither or both of height data and/or explicit detonation instructions.

The tracking system 10 may also be used to adjust ordinance trajectory,where appropriate. For example, as shown in FIG. 18, the tracking system10 may track a plurality of the ordinances 242 as they travel throughthe air by tracking the retro-reflective markers 24 positioned on theircasings 260 (see FIG. 17). The ordinances 242, in some embodiments, maybe fired from cannons 290 mounted on robotic arms 292 attached to a base294 on the ground 192. The robotic arms 292 may have articulation 296along at least one axis, for example between one and six, to allow theordinances 242 to be fired along any appropriate trajectories for thefirework show 240.

In operation, the tracking system 10 may track the ordinances 242 andmay also track their associated burst patterns 298 to determine launchtrajectory and the location where the ordinances 242 ultimatelydetonated using, for example, firework trajectory control circuitry 300.In certain embodiments, the control unit 18 may have a predeterminedfirework show sequence stored in memory 22 (see FIG. 1), where the showsequence includes associated burst patterns, timing, trajectory, and soforth. The control unit 18 may perform substantially real-timecomparisons between the tracked locations of the ordinances 242 andtheir burst patterns 298 to stored locations and associated burstpatterns, and the timing associated with this stored information, and,using the trajectory control circuitry 300, cause actuation of therobotic arms 292 to adjust a position of the cannons 290. The adjustmentmay be performed so that the monitored trajectories of the ordinances242 and locations of burst patterns 298 are appropriately correlated tothe corresponding information stored in memory 22 associated with thestored firework show.

As noted above, in certain embodiments, the ordinance 242 may notinclude a lift charge. Instead, the ordinance 242 may be launched out ofthe cannons 290 using a compressed gas (e.g., compressed air) providedby a compressed gas source 302. In this regard, the amount of compressedgas (e.g., a pressure of the compressed gas) provided to the cannons 290may determine, at least in part, a trajectory of the ordinance 242through the air, how high the ordinance 242 is before it detonates, andso forth. As illustrated, the control unit 18 may be communicativelycoupled to the compressed gas source 302, and may adjust the amount ofcompressed gas provided by the compressed gas source 302 to the cannons290 to adjust a launch velocity of the ordinance 242 out of the cannons290. For example, such adjustments may be provided based on comparisonsbetween an expected (e.g., stored, reference) trajectory of theordinance 242 and a measured trajectory of the ordinance 242. In thisway, subsequent ordinances 242 having substantially the sameconfiguration as the tracked ordinances 242 may have trajectories thatare adjusted by the control unit 18 to more closely match the stored orreference trajectory.

While only certain features of the present embodiments have beenillustrated and described herein, many modifications and changes willoccur to those skilled in the art. It is, therefore, to be understoodthat the appended claims are intended to cover all such modificationsand changes as fall within the true spirit of the invention.

1. An amusement park surveying system, comprising: an amusement parkfeature comprising a retro-reflective marker covered by a surfacetreatment of the amusement park feature; an emitter configured to emitelectromagnetic radiation toward the retro-reflective marker; a detectorconfigured to detect retro-reflection of the electromagnetic radiationfrom the retro-reflective marker while filtering electromagneticradiation that is not retro-reflected; and a control systemcommunicatively coupled to the detector and comprising processingcircuitry configured to: monitor the retro-reflected electromagneticradiation from the retro-reflective marker; determine an intensity ofthe retro-reflected electromagnetic radiation from the retro-reflectivemarker; compare the intensity of the retro-reflected electromagneticradiation from the retro-reflective marker to a stored intensity in thecontrol system; and evaluate a degree of degradation of the surfacetreatment of the amusement park feature based on the comparison betweenthe intensity and the stored intensity.
 2. The system of claim 1,wherein the surface treatment of the amusement park feature comprisespaint.
 3. The system of claim 1, wherein the processing circuitry of thecontrol system is configured to determine an amount of exposure of theretro-reflective marker with respect to the surface treatment of theamusement park feature based on the intensity of the electromagneticradiation from the retro-reflective marker.
 4. The system of claim 3,wherein the processing circuitry of the control system is configured tooutput a user-perceivable indication upon determining that theretro-reflective marker is fully exposed with respect to the surfacetreatment of the amusement park feature.
 5. The system of claim 4,wherein the user-perceivable indication comprises a notification toreapply the surface treatment to the amusement park feature and over theretro-reflective marker.
 6. The system of claim 1, wherein the amusementpark feature is a building.
 7. The system of claim 1, wherein theprocessing circuitry of the control system is configured to monitor theretro-reflected electromagnetic radiation from the retro-reflectivemarker upon reapplication of the surface treatment to the amusement parkfeature to determine the stored intensity.
 8. The system of claim 1,wherein processing circuitry of the control system is configured todetermine whether a spectral shift has occurred on the amusement parkfeature based on the comparison between the intensity and the storedintensity.
 9. The system of claim 8, wherein the spectral shiftcomprises paint fading.
 10. An amusement park surveying system,comprising: an amusement park feature comprising a retro-reflectivemarker; an emitter configured to emit electromagnetic radiation towardthe retro-reflective marker; a detector configured to detectretro-reflection of the electromagnetic radiation from theretro-reflective marker while filtering electromagnetic radiation thatis not retro-reflected; and a control system communicatively coupled tothe detector and comprising processing circuitry configured to: monitora first phase of electromagnetic radiation emitted from the emittertoward the retro-reflective marker; monitor a second phase ofretro-reflected electromagnetic radiation from the retro-reflectivemarker; determine a phase difference between the first phase and thesecond phase; and evaluate a distance between the emitter and theretro-reflective marker based on the phase difference.
 11. The system ofclaim 10, wherein the processing circuitry of the control system isconfigured to determine whether the amusement park feature has shiftedbased on the distance between the emitter and the retro-reflectivemarker.
 12. The system of claim 11, wherein the amusement park featurecomprises a track, and wherein the processing circuitry of the controlsystem is configured to determine movement of the track relative to asupport configured to support the track.
 13. The system of claim 10,wherein the processing circuitry of the control system is configured tomonitor the first phase of the electromagnetic radiation emitted fromthe emitter toward the retro-reflective marker by modulating theelectromagnetic radiation using a quartz crystal oscillator.
 14. Thesystem of claim 10, wherein the processing circuitry of the controlsystem is configured to determine a frequency of vibration of theamusement park feature based on the phase difference.
 15. The system ofclaim 10, comprising an additional amusement park feature having anadditional retro-reflective marker, wherein the processing circuitry ofthe control system is configured to: monitor a third phase ofelectromagnetic radiation emitted from the emitter toward the additionalretro-reflective marker; monitor a fourth phase of additionalretro-reflected electromagnetic radiation from the additionalretro-reflective marker; determine an additional phase differencebetween the third phase and the fourth phase; and evaluate an additionaldistance between the emitter and the additional retro-reflective markerbased on the additional phase difference.
 16. The system of claim 15,wherein the processing circuitry of the control system is configured todetermine the phase difference and the additional phase differencesubstantially simultaneously.
 17. A method of surveying amusement parkfeatures, comprising: monitoring retro-reflected electromagneticradiation from a retro-reflective marker disposed on an amusement parkfeature; determining a parameter of the retro-reflected electromagneticradiation from the retro-reflective marker; comparing the parameter ofthe retro-reflected electromagnetic radiation from the retro-reflectivemarker to a target parameter; and determining whether the amusement parkfeature is in need of maintenance based on the comparison between theparameter and the target parameter.
 18. The method of claim 17, whereinthe parameter comprises a first phase of the retro-reflectedelectromagnetic radiation, the target parameter comprises a second phaseof emitted electromagnetic radiation from an emitter and directed towardthe retro-reflective marker, and determining whether the amusement parkis in need of maintenance based on the comparison between the parameterand the target parameter comprises determining a distance between theemitter and the retro-reflective marker based on the comparison betweenthe parameter and the target parameter.
 19. The method of claim 18,comprising determining whether the amusement park feature has shiftedbased on the distance between the emitter and the retro-reflectivemarker.
 20. The method of claim 17, wherein the parameter comprises anintensity of the retro-reflected electromagnetic radiation, the targetparameter comprises a stored intensity of the retro-reflectedelectromagnetic radiation, and determining whether the amusement park isin need of maintenance based on the comparison between the parameter andthe target parameter comprises determining a degree of degradation of asurface treatment applied over the retro-reflective marker disposed onthe amusement park feature.